Dust guard structure

ABSTRACT

An apparatus includes a particle trap coupled to a first surface of an enclosure, wherein the first surface of the enclosure is opposite a top surface of a circuit board. A particle guard coupled to the top surface on a first side of the circuit board located in the enclosure, wherein the enclosure includes one or more apertures on a second surface of the enclosure where the first side of the circuit board is introduced to an external airflow.

FIELD OF THE INVENTION

This disclosure relates generally to dust guard structures, and inparticular, to dust guard structures mounted on circuit boards.

BACKGROUND OF THE INVENTION

Computer cooling is the removal of waste heat produced by computercomponents located in computer systems, such as servers, where computercooling allows for the computer components to operate within apermissible temperature range. Computer components that are susceptibleto temporary malfunction or permanent damage due to overheating includeintegrated circuits such as computer processing units (CPUs), chipset,graphic cards, and hard disk drives. Air-cooling of the computercomponents typically includes the usage of cooling fans that aid in theremoval of heat from enclosures housing the computer components. Air isintroduced on the inlet side of the enclosure housing the computercomponents and exhausted from the outlet side of the enclosure. Theintroduction of the air on the inlet side typically includes dustparticles and other contaminates, which are passed into the enclosurehousing the computer components.

SUMMARY

An embodiment of the present invention discloses an apparatus for aparticle trap comprising the particle trap coupled to a first surface ofan enclosure, wherein the first surface of the enclosure is opposite atop surface of a circuit board. A particle guard coupled to the topsurface on a first side of the circuit board located in the enclosure,wherein the enclosure includes one or more apertures on a second surfaceof the enclosure where the first side of the circuit board is introducedto an external airflow.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following detailed description, given by way of example and notintended to limit the disclosure solely thereto, will best beappreciated in conjunction with the accompanying drawings, in which:

FIG. 1 depicts a circuit board with dust guard structure, in accordancewith an embodiment of the present invention.

FIG. 2 depicts a top view of the circuit board with dust guard structureof FIG. 1, in accordance with one embodiment of the present invention.

FIG. 3a depicts a side view of a block dust guard structure, inaccordance with one embodiment of the present invention.

FIG. 3b depicts a side view of a wedge dust guard structure, inaccordance with one embodiment of the present invention.

FIG. 3c depicts a side view of a partially enclosed dust guardstructure, in accordance with one embodiment of the present invention.

FIG. 4 depicts a block dust guard structure with an adhesive film, inaccordance with one embodiment of the present invention.

FIG. 5 depicts a wedge dust guard structure with an adhesive filmmounted on a surface of a circuit board enclosure, in accordance withone embodiment of the present invention.

DETAILED DESCRIPTION

Detailed embodiments of the present invention are disclosed herein withreference to the accompanying drawings; however, it is to be understoodthat the disclosed embodiments are merely illustrative of potentialembodiments of the invention and may take various forms. In addition,each of the examples given in connection with the various embodiments isalso intended to be illustrative, and not restrictive. This descriptionis intended to be interpreted merely as a representative basis forteaching one skilled in the art to variously employ the various aspectsof the present disclosure. In the description, details of well-knownfeatures and techniques may be omitted to avoid unnecessarily obscuringthe presented embodiments.

FIG. 1 depicts a circuit board with dust guard structure, in accordancewith an embodiment of the present invention.

In this embodiment, circuit board 102 includes inlet side 104 and outletside 106. Inlet side 104 of circuit board 102 represents a front side ofcircuit board 102, where cooling air is introduced (i.e., exposed) tocircuit board 102. Outlet side 106 represents a rear side of circuitboard 102, where the cooling air is exhausted away from circuit board102. Dust guard 108 is coupled to circuit board 102 on inlet side 104,where airflow rate is greater when compared to outlet side 106. As aresult of the cooling air being introduced to circuit board 102, ambienttemperatures are lower and relative humidity levels are higher on inletside 104 when compared to outlet side 106. Dust guard 108, also referredto as a particle guard in some embodiments, prevents contaminants frombeing passed over electronic components located near inlet side 104 oncircuit board 108. By preventing contaminants from passing over theelectronic components on circuit board 106, the electronic componentsare exposed to less containments that can build up around each of theelectronic components resulting in corrosion and other electricfailures. In one embodiment, dust guard 108 is coupled to circuit board102 utilizing any adhesive known in the art. In another embodiment, dustguard 108 is coupled to circuit board 102 utilizing clip attachmentsthat run through circuit board 102 (i.e., through-hole mount). In yetanother embodiment, dust guard 108 is soldered to circuit board 102.

In one embodiment, two or more circuit boards 102 are arranged inparallel in a stacked manner. A cooling fan introduces air onto the twoor more circuit board 102 on inlet side 104 and exhausted on outlet side106. Dust guard 108 located on inlet side 104 on each of the two or morecircuit boards arranged in parallel, prevents particles from being builtup on electronic components on each of the two or more circuit boards.In another embodiment, circuit board 102 is located in an enclosure. Theenclosure acts as a conduit for passing cooling air from inlet side 104of circuit board 102 to outlet side 106, where the cooling air isexhausted out of the enclosure.

FIG. 2 depicts a top view of the circuit board with dust guard structureof FIG. 1, in accordance with one embodiment of the present invention.

In this embodiment, cooling airflow 202 is being introduced to inletside 104 of circuit board 106, from FIG. 1. Outline 204 represents anexample air streamline created by cooling airflow 202 over circuit board106, where dust guard 108 creates the example streamline shown byoutline 204. The location of outline 204 is dependent on an airflow rateof cooling airflow 202 and dimensions of dust guard 108. Dust guard 108,outline 204, and centerline 206 enclose to form area 212 on portion 208of circuit board 102, where area 212 represents an area of reducedairflow. The height of area 212 is greatest near dust guard 108 andprogressively decreases towards centerline 206 of circuit board 104.Outline 204 and centerline 206 enclose to form area 214 on portion 210of circuit board 102.

Portion 210 of circuit board 102 experience higher temperatures withlower relative humidity compared to portion 208 of circuit board 208.Higher temperature with lower relative humidity allows for contaminantsto pass over electronic components located in portion 210 of circuitboard 102, without the contaminants attaching to electronic components.Electronic components in area 214 of portion 210 experience stagnantairflow on a lower portion of the electronic components due to dustguard 108 and accelerated airflow (i.e., cooling airflow 202) on anupper portion of the electronic components. The stagnant airflow in area214 allows higher temperatures and lower relative humidity for theseelectrical components. Components in area 212 experience lowertemperatures and higher relative humidity. Dimensions of dust guard 108including width, length, height, and shape are dependent on applicationparameters of dust guard 108 including circuit board dimensions, circuitboard enclosure dimensions, circuit board electronic componentdimensions, and airflow rate over the circuit board.

FIG. 3a depicts a side view of a block dust guard structure, inaccordance with one embodiment of the present invention.

In this embodiment, electronic component 302 includes electricalconnections 304 through which electronic component 302 connects tocircuit board 306. Dust guard 308 located at an inlet side of circuitboard 306 provides protection from contaminants coming into contact withelectronic connections 304 of electronic component 302. In thisembodiment, dust guard 308 is a block shaped dust guard structurestretching the width of the inlet side of circuit board 306. Dust guard308 prevents particles (i.e., contaminates) from collecting onelectronic connections 304 by diverting air away from electroniccomponent 302 at the leading edge of the card. Cooing airflow passesover a top portion of electronic component to provide cooling and heatevacuation from electronic component 302, without introducing particlesto electronic connections 304 located in a bottom portion of electroniccomponent 302.

FIG. 3b depicts a side view of a wedge dust guard structure, inaccordance with one embodiment of the present invention.

In this embodiment, dust guard 310 is a wedge shaped dust guardstructure stretching the width of the inlet side of circuit board 306.Dust guard 310 prevents particles (i.e., contaminates) from collectingon electronic connections 304 by diverting air away from electroniccomponent 302 at the leading edge of the card. Cooing airflow passesover a top portion of electronic component 302 to provide cooling andheat evacuation from electronic component 302, without introducingparticles to electronic connections 304 located in a bottom portion ofelectronic component 302. In this embodiment, dust guard 310 includes afirst surface and a second surface arranged in a manner to form an acuteangle. The first surface and a top surface of circuit board 306 arearranged to form an acute angle, while the second surface and the topsurface of circuit board 306 are arranged to form a right angle. Inother embodiments, the first surface can include an adhesive film, aplurality of adhesive films stacked in arrangement, an abrasive coating,and/or an electrostatically charged film for collecting particles (i.e.,contaminants).

FIG. 3c depicts a side view of a partially enclosed dust guardstructure, in accordance with one embodiment of the present invention.

In this embodiment, dust guard 312 is a partially enclosed dust guardstructure stretching the width of the inlet side of circuit board 306.Dust guard 312 prevents particles (i.e., contaminates) from collectingon electronic connections 304 by diverting air away from electroniccomponent 302 at the leading edge of the card. Cooling airflow passesover a top portion of electronic component to provide cooling and heatevacuation from electronic component 302, without introducing particlesto electronic connections 304 located in a bottom portion of electroniccomponent 302. Dust guard 312 includes a first surface facing an inletside of circuit board 306 and a second surface facing electroniccomponent 302. A third surface of dust guard 312 extends over the firstsurface to create a partially enclosed area for collecting contaminantsin dust guard 312. In other embodiments, the first surface can includean adhesive film, a plurality of adhesive films stacked in arrangement,an abrasive coating, and/or an electrostatically charged film forcollecting particles (i.e., contaminants).

FIG. 4 depicts a block dust guard structure with an adhesive film, inaccordance with one embodiment of the present invention.

In this embodiment, circuit board 402 includes dust guard 406 coupled toinlet side 404 of circuit board 402. Dust guard 406 further includesfilm 408 for capturing particles (i.e., contaminants), that otherwisewould be diverted by dust guard 406. In this embodiment, film 408 is aremovable double-sided adhesive film that captures particles prior tothe particles being diverted past the electronic components on circuitboard 402. The removable double-sided adhesive film allows for areplacement film 408 to be re-applied in pre-determined serviceintervals. In another embodiment, film 408 is one of a plurality (e.g.,20) of removable single-sided or double-sided adhesive films arranged ina stacked manner. As film 408 collects particles over a period of time,film 408 along with any attached particles is removed exposing anotherfilm stacked below film 408. The plurality of stacked films allows forquicker servicing of dust guard 406 and shorter down time of circuitboard 402.

In yet another embodiment, film 408 includes an abrasive coating (i.e.,rough surface) to allow film 408 on dust guard 406 to capture particles.The abrasive coating includes a plurality of abrasive grains in whichfilm 408 on dust guard 406 can capture corrosive particles (e.g., dust).The abrasive grains on the abrasive coating allow for the particle toremain on the surface of film 408 on dust guard 406, regardless of thecooling airflow rate that circuit board 402 experiences. In yet anotherembodiment, film 408 includes an electrostatic charge capable ofattracting contaminates, such as dust particles. In this embodiment,film 408 is one of a plurality of removable electrostatically chargedfilms that are serviceable dependent on the duration that each filmholds the electrostatic charge. As a film (e.g., film 408) on dust guard406 losses an electrostatic charge capable of attracting particles, thefilm reaches a servicing point and the film can be removed to expose anew electrostatically charged film.

FIG. 5 depicts a wedge dust guard structure with an adhesive filmmounted on a surface of a circuit board enclosure, in accordance withone embodiment of the present invention.

In this embodiment, electronic component 502 includes electricalconnections 504 through which electronic component 502 connects tocircuit board 506. Circuit board 506 is located in enclosure 510, whereenclosure 510 is one of a plurality of enclosure located, for example,on a computer server rack. In this embodiment, enclosure 510 includes aplurality of apertures on an inlet side of circuit board 506 to allowcooling airflow to enter enclosure 510. Enclosure 510 also includes aplurality of apertures on an outlet side of circuit board 506 to exhaustthe cooling airflow out of enclosure 510. In other embodiment, enclosure510 can included a plurality of apertures on any side to maximize theeffectiveness of the cooling airflow being introduced onto circuit board506.

Dust guard 508 located at the inlet side of circuit board 506 providesprotection from contaminants coming into contact with electronicconnections 504 of electronic component 502 as the contaminants enterenclosure 510. In this embodiment, dust guard 508 is a wedge shaped dustguard structure stretching the width of the inlet side of circuit board506. Dust guard 508 prevents particles (i.e., contaminates) fromcollecting on electronic connections 504 by diverting air away fromelectronic component 302 at the leading edge of the card. Particle trap512 located inside enclosure 510 on a top portion of enclosure 510captures contaminants diverted by dust guard 508. In this embodiment,particle trap 512 is a removable double-sided adhesive film thatcaptures particles prior to the particles moving through enclosure 510and onto other electronic components on circuit board 506. The removabledouble-sided adhesive film allows for a particle trap 512 to bere-applied in pre-determined service intervals.

In another embodiment, particle trap 512 is one of a plurality (e.g.,20) of removable single-sided or double-sided adhesive films arranged ina stacked manner. As particle trap 512 collects particles over a periodof time, particle trap 512 along with any attached particles is removedexposing another film stacked below particle trap 512. The dimensionsand shape of particle trap 512 is dependent on the dimensions and shapeof dust guard 508, to maximize the effectiveness of particle trap 512.For example, altering an angle of the wedge shaped dust guard 508 altersa location to where containments are diverted by dust guard 508. Thegreater an angle of the wedge shaped dust guard 508, the closer particledust guard 508 is located to the inlet side of circuit board 506.Reversely, the smaller an angle of the wedge shaped dust guard 508, thefurther particle dust guard 508 is located from the inlet side ofcircuit board 506.

In yet another embodiment, particle trap 512 includes an abrasivecoating (i.e., rough surface) to allow particle trap 512 to captureparticles diverted by dust guard 508. The abrasive coating includes aplurality of abrasive grains in which particle trap 512 can capturecorrosive particles (e.g., dust). In this embodiment, particle trap 512utilizes an adhesive back portion for coupling to an inner surface ofenclosure 510 and the abrasive coating on the top portion for capturingthe particles diverted by dust guard 508.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting to the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

Having described preferred embodiments of a dust guard structure (whichare intended to be illustrative and not limiting), it is noted thatmodifications and variations may be made by persons skilled in the artin light of the above teachings. It is therefore to be understood thatchanges may be made in the particular embodiments disclosed which arewithin the scope of the invention as outlined by the appended claims.

What is claimed is:
 1. An apparatus comprising: a particle trap coupledto a first surface of an enclosure, wherein the first surface of theenclosure is opposite a top surface of a circuit board; a particle guardcoupled to the top surface on a first side of the circuit board locatedin the enclosure, wherein the enclosure includes one or more apertureson a second surface of the enclosure where the first side of the circuitboard is introduced to an external airflow, wherein the particle guardis wedge shaped; an electrostatically charged film coupled to a firstsurface of the particle guard, wherein the first surface of the particleguard forms an acute angle with the top surface of the circuit board;and a plurality of electronic components coupled to the circuit boardvia a plurality of electronic connections, wherein a height of theparticle guard is greater than a height of each of all the plurality ofelectronic connections.
 2. The apparatus of claim 1, wherein theparticle trap includes an adhesive film coupled to a first surface ofthe particle trap opposite the top surface of the circuit board.
 3. Theapparatus of claim 2, wherein the adhesive film coupled to the firstsurface of the particle trap is a first adhesive film out of a pluralityof adhesive films stacked in arrangement.
 4. The apparatus of claim 1,wherein the particle trap further comprises an abrasive coatingincluding a plurality of abrasive grains coupled to a first surface ofthe particle trap opposite the top surface of the circuit board.
 5. Theapparatus of claim 1, wherein dimensions and a location of the particletrap is dependent on dimensions and a location of the particle guard. 6.The apparatus of claim 1, wherein the particle guard diverts externalairflow towards the particle trap.
 7. The apparatus of claim 6, whereinthe enclosure includes one or more apertures on a third surface of theenclosure opposite the second surface of the enclosure for exhaustingthe external airflow introduced at the first side of the circuit board.